1. Field of the Invention
The present invention relates a machine for renewing and laying a railway track including two rails and ties supported on a ballast bed, which comprises an elongated machine frame having two opposite ends and undercarriages supporting the machine frame at the ends thereof, the undercarriages including at one of the machine ends an undercarriage which is vertically adjustable relative to the machine frame, the vertically adjustable undercarriage not being track-bound, and a track-bound undercarriage which is arranged adjacent the vertically adjustable undercarriage. The machine also comprises a device for receiving old ties mounted on the machine frame, a device for laying new ties mounted on the machine frame, a vertically adjustable device for planing the ballast bed mounted on the machine frame between said devices, and means mounted on the machine frame for guiding old and new rails.
2. Description of the Prior Art
U.S. Pat. No. 4,184,431 discloses a machine of this type, which may be used for laying a new track or for renewing an old track. The machine comprises a bridge-like, elongated machine frame supported by undercarriages at the opposite ends thereof and tie transport cars are coupled to its rear end, relative to the operating direction, which is the same for renewing or laying track. A tracked vehicle is vertically adjustably mounted on the machine frame immediately behind the front bogie and is steerable when lowered onto the ballast bed. The operating devices for receiving and laying the ties are mounted behind the tracked vehicle on a carrier frame which may be vertically adjusted, the device for receiving the old ties and the ballast bed planing device being additionally vertically adjustable relative to the carrier frame.
In a track renewal operation, the machine runs with its front bogie on the old track, while the tracked vehicle is retracted, while the rear bogie runs on the newly laid track. The exchange of the old ties and rails for the new ties and rails, as well as the planing of the ballast bed, is effectuated between the front and rear bogies while the machine advances continuously, and a gantry is provided to deliver the new ties and remove the old ties. When laying a new track on a prepared ballast bed, the tracked vehicle is lowered, causing the front end of the machine frame and the front bogie to be raised so that the front machine end rolls along the ballast bed as it is supported on the tracked vehicle. The rear bogie runs on the track newly laid by the operating devices on the machine frame while the device for receiving the old ties and the ballast bed planing device are raised into their inoperative positions. Because the rails must be spread to the desired track gage within the relatively short distance between the device for laying the new ties and the rear bogie, they are subjected to considerable bending stresses, which may exceed permissible limits.
Another machine for renewing track and laying new track has been disclosed in U.S. Pat. No. 4,207,820. It comprises a two-part machine frame whose parts are linked together. One machine frame part is supported by two track-bound bogies while the other machine frame part is a trailer linked at one end to the one machine frame part while its other end is supported by a bogie. An operator's cab is mounted on the trailer part. A carrier frame for tie receiving and laying devices as well as a ballast bed planing device is linked to both machine frame parts below the joint linking the two parts together. In a track renewal operation, the machine advances in an operating direction in which the operator's cab is at the rear and the trailer bogie runs on the newly laid track while the front bogie of the one machine frame parts runs on the old track. The other bogie of the one machine frame part adjacent the joint linking the machine frame parts together does not engage the old track but the one machine frame part is supported at this point by an auxiliary bogie engaging the new rails which lie on the track shoulders adjacent the old rails. When a new track is to be laid, the machine is operated in the opposite direction, i.e. the operator's cab is in front and the front end of the trailer is supported by an auxiliary bogie on newly laid rails. A device behind the auxiliary bogie lays the new ties while the other operating devices remain inoperative and the rear bogies run on the newly laid track.
U.S. Pat. No. 5,092,247 discloses a process for converting a track renewal train into a machine for laying a new track. For this purpose, a track-bound undercarriage, which runs at the rear of the machine on the newly laid track during a track renewal operation, is carried on a self-propelled tracked vehicle which runs on the ballast bed when a new track is laid as the machine operates in the opposite direction. When the machine is converted from one to the other use, the various operating devices for exchanging the ties and rails are partly put out of operation and partly adapted for laying the new track in the opposite direction.
U.S. Pat. No. 3,691,957 discloses a mobile apparatus for laying and removing track ties along a right of way. This apparatus comprises a machine frame one of whose ends is supported on a track by a track-bound undercarriage while a track-bound undercarriage or a vertically adjustable tracked vehicle selectively support the other machine frame end either on the track or on the ballast bed when the track is raised to enable a tie exchange mechanism on the machine frame to remove the old ties and lay the new ties.
U.S. Pat. No. 4,236,452 discloses a track renewal train which includes a semi-trailer work car which carries track renewal equipment and has two selectively usable undercarriages for supporting the rear end of the work car. One of the undercarriages is a tracked vehicle for supporting the work car on the ballast bed portion where the track renewal is effected and the other undercarriage is a vertically adjustable track-bound bogie.